Rhino 7, File preview is missing in Windows Explorer

I did a fresh install of the new V7 this morning, but my file thumbnail previews are no longer working. Already checked out the McNeel Wiki and did the following steps.

-Repaired Rhino installation
-Verified thumbnails are not disabled
-Deleted thumbnail cache
-Registered the Rhino thumbnail viewer with command below

regsvr32 “C:\Program Files\Rhino 7\System\RhinoHandlers.dll”

So far all to no avail. Any other options?

Hi Mark - checking…



I have some extra information. If I open a file and save it as V7, it shows the file thumbnail when I go back to open it immediately afterward. However, if I open another file and save it the thumbnail for the previously opened file reverts back to just a file icon. No idea what’s going on.

If it’s any help, my file thumbnails still work for SolidWorks, so I don’t believe it’s a Windows setting.

@Mark_Landsaat - just in case this helps:


No, sorry. Already tried that.

Been playing around with this again to try and resolve. Have some additional information. When I copy a Rhino file from one folder to another folder, the pasted file in the new folder will create a thumbnail image.

However, this is only temporary and after a while it reverts back to just a file icon.

To make things even more confusing, files that are copied to my desktop do have a thumbnail image, but that seems to be the only location that this is true for.

Hi Mark - and files saved from V6 show the thumbnail, is that correct?

Somehow this feels kinda-maybe like an installer thing, possibly; I’ll start with that developer.
@Mark_Landsaat - are you running Rhino at the same permission level as Windows? Not using ‘run as administraor’ or something? not likely, I know, just making sure there is nothing non-standard there.


No, all my thumbnails are gone at this point. Except for the ones save on my desktop (or moved there)

-Also, if I start Rhino the recent files tab shows thumbnails. Not sure if this helps, but trying to share as much information as I can.

Hi Mark - the thumbnails are also missing if you use Rhino’s File > open and browse around? not just in independent Explorer windows? I think so, just making sure…
And of course… have you rebooted?
One more thing - a bit of a long shot but one never knows, one of my colleagues has found it helps in apparently related cases:


Yes, thumbnails are also missing when I use Rhino’s File>Open.
Just ran the testRestoreLibraryFileAssociations command and this required a restart. But also had restarted several times after I changed settings.

When I activate the preview pane in Rhino’s File>Open I do get a thumbnail preview of the file. Unfortunately none of this is helping so far.

Have we reached the point where I uninstall V7 and reinstall? Not sure if it would change anything, but it doesn’t seem like we have very many options left.

Hi Mark - yes, uninstall/reinstall. That would be the next thing to try. I am still mystified by the desktop aspect of this though…


So am I, just to show I’m not making this up, I copied a few files to my desktop see screenshot. And for good measure, a screenshot of a folder with Rhino files in it. The uninstall/reinstall will have to wait for now. I will let you know how that works out, hopefully later today. Thanks.

I’m having this very same issue on an brand new Desktop I’m trying to set up. Everything Mark is saying is the same with myself. It’s really a frustrating situation…

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Did the uninstall/install, but unfortunately still no luck. Something weird is going on. Check out the screenshot, they show my recently opened files and these do have a thumbnail preview. However the same files in their actual file location only shows the Rhino file icon. I’m at a loss of what to try next.

Hi @Mark_Landsaat,

Do you have more than one Windows 10 PC? If so, are they synchronising files and/or settings? If so you could try running disconnected from your network for a while to see if the thumbnails persist.

Also, as you are running in dark mode, have you employed any alchemy to achieve that?


p.s. I see thumbnails fine on both my machines, so it isn’t a universal problem; I am looking for what might be different about your setup.

Hi Jeremy,

Appreciate the help. Only one PC, but files are backed up to OneDrive. I can disable OneDrive to see if it makes a difference.

Nothing weird about dark mode, just changed color settings in applications, or use dark mode if available in application.

Things were working fine in Rhino 6. I don’t know what’s different, but obviously something has changed. Also didn’t think this was a universal problem, but whatever is triggering this may also be an issue for other users.


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Hi @Mark_Landsaat,

Are you familiar with the Sysinternal tools (downloadable from Microsoft)? You could run the process monitor (procmon), filtering to include events with thumbcache or iconcache in the path over an interval where you expect to see a thumbnail revert to an icon and then see what processes are accessing the various cache databases. Might give some insight into what is going on.


While I certainly appreciate the suggestion, you pretty much lost me after “Are you familiar with” :grinning:

I’ll have to come back to this at a later date again, have other work to do. Thanks though.

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I’ve installed Rhino 7 today and have same problem. There is no thumbinal preview in Windows Explorer and Adobe Bridge. With Rhino 6 all preview worked fine. Any sugestions?

Edit: When Rhino 6 is installed with Rhino 7, thumbinal preview works fine. With only Rhino 7 installed it is not showing preview.

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Did you try this:
Fix Thumbnails not showing in Onedrive folder.

Step 5 solved it for me

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